Cutting, stripping, and wrapping bit for insulated conductor wire

ABSTRACT

A bit and sleeve assembly for cutting, stripping and wrapping an insulated conductor comprising a rotary wrapping bit mounted within a fixed tubular sleeve. The bit includes a longitudinal conductor receiving groove having disposed therein a transverse cutting edge or blade insert cooperable with the sleeve to cut the conductor insulation upon commencement of the wrapping operation. The sleeve includes a radially extended wall portion forming an opening to the bit end face which is alignable with the conductor receiving groove to facilitate loading an insulated conductor into the groove. An opening in the sleeve alignable with the conductor receiving groove defines a cutting edge cooperable with the bit to cut a predetermined length of wire to be wrapped.

United States Patent 1191 Baker et al. Jan. 1, 1974 [54] CUTTING,STRIPPING, AND WRAPPING 3,023,484 3/1962 Arens et al. 29/33 F B11 FORINSULATED CONDUCTOR WIRE 3,696,482 10/1972 Tumilty 29/33 F 175Inventors: William J. Baker; Clifford L. FOREIGN PATENTS 0R APPLICATIONSGalloup, both of Reed City; John R. 533,220 I 1/1956 Canada 242/7.l7Bos, Grand Haven, all of Mich. 1731 Assi nee; Gardner-Denver Company,Quincy, jg jf fg gfgizfg jfiggg lg'g 4 Artomey-Michael E. Martin [22]Filed: Dec. 16, 1971 1211 Appl. No.: 208,79l [57] ABSTRACT A bit andsleeve assembly for cutting, stripping and wrapping an insulatedconductor comprising a rotary [52] 7/14'l 81/95 g wrapping bit mountedwithin a fixed tubular sleeve. l t C] 5 The bit includes a longitudinalconductor receiving 81 9 5 R groove having disposed therein a transversecutting 0 7g; 5/ edge or blade insert cooperable with the sleeve to cut29/3'3 the conductor insulation upon commencement of the wrappingoperation. The sleeve includes a radially extended wall portion formingan opening to the bit end [56] References Cmd face which is alignablewith the conductor receiving UNITED STATES PATENTS groove to facilitateloading an insulated conductor 2.807.810 10/1957 Belek etal. 7/14.! Rinto the groove. An opening in the sleeve alignable 3.078. 52 2/l963 Ods at l 2/717 with the conductor receiving groove defines a cutting35549-43 H971 DeRme ill/9'5 R edge cooperable with the bit to cut apredetermined 3.56l.687 2/1971 Bergmann 242/7.17 length of wire to bewrapped 3.581.608 6/197] Baker 4 8l/9.5 R 3.625.262 12/1971 Baker et al.l40/l24 6 Claims, 5 Drawing Figures CUTTING, STRIPPING, AND WRAPPING BITFOR INSULATED CONDUCTOR WIRE BACKGROUND OF THE INVENTION In the art ofmaking solderless electrical connections by wrapping a flexibleconductor wire about a terminal in a series of helical convolutions,devices are known which are operable to cut a predetermined wire lengthto be wrapped, strip the insulation, and wrap the bare conductor on theterminal. Such devices are commonly known as combination wrapping bitsor tools and they are particularly advantageous for use in makingwrapped connections in field installation and repair of communicationsequipment because they eliminate the need for separate tools to performeach operation. Combination cutting, stripping and wrapping bits aredisclosed in US. Pats. Nos. 2,682,063 to HA. Miloche; 2,807,810 to E.Belek et al; 3,393,715 to PG. Finn; and 3,544,243 to R.A. DeRose et al.

A deficiency realized with certain prior art stripping and wrappingtools includes the provision of a sleeve which only partially surroundsa rotatable bit device. These bit and sleeve combinations are designedto provide for loading the conductor wire into the bit device bysubstantially transverse movement of the wire with respect to thelongitudinal axis of the bit to lay the wire into the receiving portionsof the bit and sleeve. Partial sleeves whether fixed or rotatable do notprovide for suitable containment or support of the wire prior to andduring the stripping and wrapping operations nor do they suitably retainthe stripped piece of insulation to prevent entanglement of same in thebit as it rotates. It has been determined that containment of theconductor portion which is to be stripped and wrapped to prevent anykinking or bending is important to providing wrapped connections whichare consistently tight on the terminal within close tolerances. Also, ithas been determined that stripping and wrapping devices having rotatingsleeves and devices having bits without sleeves have proven to betroublesome in use with hand-held conductor wrapping tools because theyusually catch and entangle the length of wire leading away from the endportion being wrapped.

Prior art stripping and wrapping bits are also characterized for themost part by integrally formed cutting edges for cutting through theinsulation to be stripped. Integral cutting notches or edges aredisadvantageous in that damage to or dulling of the cutting edgerequires costly repair work on the bit or replacement of the completebit.

Another longstanding problem in the art of combination conductorwrapping bits concerns the provision of a bit and sleeve constructionwhich does not require the sleeve to be axially movable with respect tothe bit but which still provides for rapid and easy insertion of theconductor end to be stripped and wrapped into the conductor receivinggroove in the bit without bending or kinking the conductor itself.Particular care must be taken not to kink or bend the conductor beforewrapping because such action will increase the extraction force requiredto withdraw the wire from the conductor receiving groove and will,accordingly, result in overstressed wrapped connections.

SUMMARY OF THE INVENTION The present invention provides improved meansfor cutting, stripping and wrapping insulated conductor wire whereby asingle rotary tool of simple construction and requiring a minimum ofoperator skill may be used to prepare and wrap insulated conductors.

The present invention also provides a combination bit for cutting apredetermined length of conductor to be wrapped, stripping apredetermined length of insulation from the conductor end, and wrappingthe stripped conductor end portion about a terminal in one continuousoperation. With the stripping and wrapping bit of the present inventionsuperior containment of the conductor portion to be stripped and wrappedis provided to prevent bending and entanglement of the conductor orinsulation. Furthermore, with the present invention entanglement ordamage to the conductor portion leading away from the stripped endportion is also prevented.

The present invention further provides a combination stripping andwrapping bit for insulated conductor wire in which the strippedinsulation portion is retained in the conductorreceiving groove duringthe wrapping operation and is automatically ejected by inserting thenext piece of insulated conductor preparatory to a stripping andwrapping operation. Moreover, the present invention provides for astripping and wrapping bit for insulated conductor wire which is easilyloaded with a conductor end portion without bending or jamming theconductor itself.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a side view of a portablerotary tool including the combination conductor wrapping bit and sleeveassembly of the present invention;

FIG. 2 is a transverse view of the end face of the conductor wrappingbit and sleeve assembly of the present invention;

FIG. 3 is a longitudinal section view taken along the line 3-3 of FIG.2;

FIG. 4 is a transverse section view taken along the line 44 of FIG. 3;

FIG. 5 is a transverse section view taken along the line 5-5 of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing arotary power tool is illustrated in FIG. 1 and generally designated bythe numeral 10. The tool 10 illustrated is of the self-containedelectric type having a battery contained within the handle portion 12for driving a suitable motor, not shown, disposed within the toolhousing. The tool 10 is intended to be exemplary of a type of tool whichmay suitably be used with the present invention. Those skilled in theart will recognize that other types of tools including fluid operated aswell as manually actuated types may also be used.

The tool 10 is adapted to support and drive "an improved device,generally designated by the numeral 14, for cutting, stripping, andwrapping an insulated conductor on a terminal. The tool 10 includes ahollow nose portion 16 in which is journaled a rotary spindle l8suitably connected to the aforementioned motor. The nose portion 16 alsoincludes a stationary cylindrical collet and nut assembly 20 comprisingmeans for removably retaining an elongated tubular sleeve 22nonrotatably with respect to the tool 10. Rotatably disposed within thetubular sleeve 22 is an elongated cylindrical member 24 comprising a bitwhich is cooperable with the sleeve to operate on a flexible insulatedconductor wire by cutting and stripping a predetermined length ofinsulation from the conductor end portion and wrapping the stripped endportion on a suitable terminal. The bit 24 includes a cylindrical endportion 26 having a transverse surface 28 and a projection 30 which isin driving engagement with a complementary projection 32 on the spindle18. As shown in FIG. 1 the transverse surface 28 is engaged with one endof the sleeve 22 within the collet 20 to prevent unintentionaldisplacement of the bit from the sleeve.

Referring to FIGS. 2 through 5, the bit 24 includes at its opposite enda transverse end face 34. A terminal receiving bore 36 is disposed inthe bit and opens to the end face 34. Disposed about the bore 36 is agenerally U-shaped axially sloping surface 38 which intersects thetransverse end face 34 and a parallel transverse surface 40. The surface38 is provided for camming a flexible conductor wire onto a terminalpost in a known way and disclosed in detail in US. Pat. No. 3,078,052 toW.L. Olds et al. The end face configuration of the bit 24 is intended tobe exemplary and it will be understood that the novel features of theimproved stripping and wrapping device 14 may be used with otherwrapping bit end face configurations.

The bit 24 is further characterized by an elongated conductor receivinggroove 42 parallel to and radially offset from the terminal receivingbore 36. The groove 42 has a generally U-shaped cross sectionalconfiguration and opens to the periphery of the bit. The groove 42 alsoopens at one end to the end face 34 of the bit. The opposite end of thegroove 42 is characterized by a sloping surface portion 44 which isadjacent an opening 46 in the wall of the tubular sleeve 22. The bit 24also includes a substantially transverse slot 48 spaced a predetermineddistance from the end face 34 in which is removably disposed a thinmetal blade 50 having a notch forming an insulation cutting edge 52. Thespacing of the blade 50 from the end face 34 provides for at least apartial convolution of insulated conductor to be wrapped on a terminal.The slot 48 is formed at a slight angle, about five degrees, withrespect to a plane perpendicular to the longitudinal axis of the bit 24to facilitate the cutting action of the edge 52. The cutting blade 50 isretained in the slot 48 by the surrounding sleeve 22. The cutting edge52 may also be formed integral with the bit 24, however, the removableblade 50 provides for rapid and economical replacement ofthe cuttingedge without replacing the entire bit. As may be appreciated fromviewing the drawing, the conductor receiving groove 42 is dimensioned toaccommodate an insulated conductor and the notch forming the cuttingedge 52 is dimensioned to be slightly greater in width than the diameterof the conductor wire. Accordingly, when an insulated conductor isforced radially, with respect to the bit axis, into the groove 42 theedge 52 makes at least a partial circumferential cut through theconductor insulation.

The tubular sleeve 22 substantially surrounds the bit 24 in closefitting relationship and encloses a major portion of the groove 42. Thesleeve 22 includes a pair of notches 54 and 55 opening to the end of thesleeve adjacent the end face 34 and disposed diametrically opposite eachother. The sleeve 22 further includes a radially outwardly relievedtubular wall portion 56 which also extends axially away from the endofthe sleeve and beyond the insulation cutting blade 50. The wall portion 56 forms a guide surface 58 having a portion 61 which slopesradially inwardly with respect to the longitudinal axis of the bit. Theguide surface 58 provides means for inserting an insulated conductorlongitudinally from the open end of the sleeve past the cutting blade50, into the groove 42, and toward the opening 46 in the sleeve. Asshown in FIGS. 2 and 4 the blade 50 includes relieved portions 53 whichprovide clearance for inserting a conductor along the guide surface 58and past the blade. The guide surface 58 may be formed by a suitablemetal forming process by displacement of the tubular sleeve wall.

As shown in FIGS. 2 through 5 the'guide surface 58 and opening 46 in thesleeve are disposed in alignment with the conductor receiving groove 42prior to insertion ofa conductor to be stripped and wrapped. A suitableindexing mechanism 59 in the tool 10 provides for indexing the rotatablebit 24 to the position shown at the termination of the previousoperating cycle of the tool. An insulated conductor C, shown by dashedlines in FIGS. 2 and 3, may be manually inserted from the open end ofthe sleeve 22 through the opening formed by the extended wall portion 56and guided into the groove 42 by the guide surface 58. The conductor Cis inserted into the groove until a small portion 63 extends out throughthe opening 46 in the sleeve to assure that a predetermined length ofstripped conductor portion will be provided for wrapping. When theconductor C is inserted in the groove the tool operator trains theconductor through the notch 54, FIG. 2, and holds the portion 62 leadingaway from the inserted end along the exterior of the sleeve. Thedirection of bit rotation is indicated by the arrow in FIG. 2. If it wasdesired to rotate the bit in the opposite direction, the notch 55 wouldbe used.

After insertion of the conductor in the bit 24, the tool is placed overa terminal, not shown, in a known way and the tool motor is energized torotate the bit. Almost immediately on commencing rotation the conductorend portion 63 is severed by the cutting edge 60 formed by thelongitudinal side of opening 46 in the sleeve as the groove 42 movespast the opening. The conductor C, held stationary with respect to thesleeve 22 at the notch 54, is pulled down into the notch in theinsulation cutting blade 50 due to the rotational movement of the bitwhereby a partial cut through the insulation is made without nicking theconductor wire. The forcing of the conductor C into the notch formingthe cutting edge 52 is assisted by engagement of the conductor by theinner wall surface of the sleeve as the groove 42 rotates away from theopening formed by the wall portion 56. Many types of insulation requireonly a partial transverse cut to provide for total severance by tearingthe remaining uncut portion without extruding the insulation remainingon the conductor. Accordingly, with the bit and sleeve assemblydisclosed, continued rotation of the bit 24 will cause completeseverance of the insulation at the blade 50 as the conductor iswithdrawn from the groove 42 and wrapped around a terminal.

As the conductor C is withdrawn from the groove 42 by continued rotationof the bit the severed insulation will be retained in the groove by thecompletely circumferential tubular sleeve and the blade 50 and will beprevented from becoming entangled in the bit or sleeve. Moreover, due tothe fact that the sleeve 22 is stationary there is no danger ofentangling the conductor portion 62 leading away from the bit end face34.

The severed insulation portion will remain in the groove 42 and will beejected through the opening 46 by insertion of an insulated conductor inpreparation for a succeeding operation of the tool 10.

As may be appreciated from the foregoing description, the improved bitand sleeve combination disclosed herein provides for a relatively simpleoperation to load an insulated conductor into the groove 42 withoutbending or kinking the conductor wire thanks to the guide surface 58formed by the extended wall portion 56. Moreover, the superiorcontainment characteristics of the bit and sleeve prevent accidentaldisplacement and entanglement of the conductor or the insulation portionbeing stripped during the stripping and wrapping process. It isparticularly significant that the stripped insulation portion isretained in the groove 42 until completion of the operating cycle of thetool whereby the insulation portion is not free to fall into the workarea or become entangled in the conductor during routing of same to thenext terminal.

We claim:

1. In a device for stripping insulation from a flexible conductor wireand wrapping said wire on a terminal in a series of helicalconvolutions:

a rotatable wrapping bit comprising;

a bit end face;

a terminal receiving bore opening to said end face;

a longitudinal wire receiving groove disposed on the periphery of saidbit and radially offset from said terminal receiving bore and opening atone end to said end face; and

a cutting edge disposed in said groove for cutting the insulation of awire disposed in said groove; and, an elongated tubular sleeve fixedsubstantially axially with respect to said bit and disposed around saidbit to substantially enclose a major portion of said groove, one end ofsaid sleeve being disposed adjacent said end fae, said sleeve includingmeans comprising a radially outwardly relieved tubular wall portionextending axially from said one end of said sleeve toward said cuttingedge and forming an opening to provide for inserting said wirelongitudinally with respect to said bit past said cutting edge and intosaid groove.

2. In a device for stripping insulation from a portion of a flexibleconductor wire and wrapping said portion on a terminal in a series ofhelical convolutions:

a rotatable wrapping bit comprising;

a bit end face;

a terminal receiving bore opening to said end face;

a conductor receiving groove disposed on the periphery of sad bitparallel to and radially offset from said terminal receiving bore andopening at one end to said end face; and

a cutting edge disposed in said groove for cutting the insulation of aninsulated conductor wire disposed in said groove; said cutting edgebeing formed on a cutting blade removably retained in a transverse slotformed in said bit and intersecting said groove; and,

an elongated tubular sleeve fixed axially with respect to said bit and.disposed around said bit to substantially enclose a major portion ofsaid groove.

3. The invention set forth in claim 2 wherein: said cutting blade isretained in said groove by said sleeve.

4. The invention set forth in claim 1 wherein:

said radially outwardly relieved wall portion forms a guide surfaceextending from said one end of said sleeve to said cutting edge.

5. The invention set forth in claim 4 wherein:

said sleeve includes an opening disposed adjacent the end of said grooveopposite said one end and forming a cutting edge for severing an endportion of a wire disposed in said groove in response to rotation ofsaid bit.

6. The invention set forth in claim 5 wherein: said guide surface isaxially aligned with said opening forming a cutting edge for severing anend portion ofa wire.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 13,781,932

DATED January 1, 1974 |NVENTOR(S) William J. Baker, et a1 it iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Column 5, line 38 "fee" should be face Column 6, line 12 "sad" should besaid,--.

Signed and Scaled this Sixth Day of February I979 [SEAL] Arrest:

RU C. M ASON DONALD W. BANNER Arresting Ojficer Commissioner of Patentsand T rldemrks

1. In a device for stripping insulation from a flexible conductor wireand wrapping said wire on a terminal in a series of helicalconvolutions: a rotatable wrapping bit comprising; a bit end face; aterminal receiving bore opening to said end face; a longitudinal wirereceiving groove disposed on the periphery of said bit and radiallyoffset from said terminal receiving bore and opening at one end to saidend face; and a cutting edge disposed in said groove for cutting theinsulation of a wire disposed in said groove; and, an elongated tubularsleeve fixed substantially axially with respect to said bit and disposedaround said bit to substantially enclose a major portion of said groove,one end of said sleeve being disposed adjacent said end fae, said sleeveincluding means comprising a radially outwardly relieved tubular wallportion extending axially from said one end of said sleeve toward saidcutting edge and forming an opening to provide for inserting said wirelongitudinally with respect to said bit past said cutting edge and intosaid groove.
 2. In a device for stripping insulation from a portion of aflexible conductor wire and wrapping said portion on a terminal in aseries of helical convolutions: a rotatable wrapping bit comprising; abit end face; a terminal receiving bore opening to said end face; aconductor receiving groove disposed on the periphery of sad bit parallelto and radially offset from said terminal receiving bore and opening atone end to said end face; and a cutting edge disposed in said groove forcutting the insulation of an insulated conductor wire disposed in saidgroove; said cutting edge being formed on a cutting blade removablyretained in a transverse slot formed in said bit and intersecting saidgroove; and, an elongated tubular sleeve fixed axially with respect tosaid bit and disposed around said bit to substantially enclose a majorportion of said groove.
 3. The invention set forth in claim 2 wherein:said cutting blade is retained in said groove by said sleeve.
 4. Theinvention set forth in claim 1 wherein: said radially outwardly relievedwall portion forms a guide surface extending from said one end of saidsleeve to said cutting edge.
 5. The invention set forth in claim 4wherein: said sleeve includes an opening disposed adjacent the end ofsaid groove opposite said one end and forming a cutting edge forsevering an end portion of a wire disposed in said groove in response torotation of said bit.
 6. The invention set forth in claim 5 wherein:said guide surface is axially aligned with said opening forming acutting edge for severing an end portion of a wire.